external/mit/lua/dist/src/lapi.c

   1 /*      $NetBSD: lapi.c,v 1.5 2015/10/08 13:21:00 mbalmer Exp $ */
   2
   3 /*
   4 ** Id: lapi.c,v 2.249 2015/04/06 12:23:48 roberto Exp
   5 ** Lua API
   6 ** See Copyright Notice in lua.h
   7 */
   8
   9 #define lapi_c
  10 #define LUA_CORE
  11
  12 #include "lprefix.h"
  13
  14
  15 #include <stdarg.h>
  16 #ifndef _KERNEL
  17 #include <string.h>
  18 #endif
  19
  20 #include "lua.h"
  21
  22 #include "lapi.h"
  23 #include "ldebug.h"
  24 #include "ldo.h"
  25 #include "lfunc.h"
  26 #include "lgc.h"
  27 #include "lmem.h"
  28 #include "lobject.h"
  29 #include "lstate.h"
  30 #include "lstring.h"
  31 #include "ltable.h"
  32 #include "ltm.h"
  33 #include "lundump.h"
  34 #include "lvm.h"
  35
  36
  37
  38 const char lua_ident[] =
  39   "$LuaVersion: " LUA_COPYRIGHT " $"
  40   "$LuaAuthors: " LUA_AUTHORS " $";
  41
  42
  43 /* value at a non-valid index */
  44 #define NONVALIDVALUE           cast(TValue *, luaO_nilobject)
  45
  46 /* corresponding test */
  47 #define isvalid(o)      ((o) != luaO_nilobject)
  48
  49 /* test for pseudo index */
  50 #define ispseudo(i)             ((i) <= LUA_REGISTRYINDEX)
  51
  52 /* test for upvalue */
  53 #define isupvalue(i)            ((i) < LUA_REGISTRYINDEX)
  54
  55 /* test for valid but not pseudo index */
  56 #define isstackindex(i, o)      (isvalid(o) && !ispseudo(i))
  57
  58 #define api_checkvalidindex(l,o)  api_check(l, isvalid(o), "invalid index")
  59
  60 #define api_checkstackindex(l, i, o)  \
  61         api_check(l, isstackindex(i, o), "index not in the stack")
  62
  63
  64 static TValue *index2addr (lua_State *L, int idx) {
  65   CallInfo *ci = L->ci;
  66   if (idx > 0) {
  67     TValue *o = ci->func + idx;
  68     api_check(L, idx <= ci->top - (ci->func + 1), "unacceptable index");
  69     if (o >= L->top) return NONVALIDVALUE;
  70     else return o;
  71   }
  72   else if (!ispseudo(idx)) {  /* negative index */
  73     api_check(L, idx != 0 && -idx <= L->top - (ci->func + 1), "invalid index");
  74     return L->top + idx;
  75   }
  76   else if (idx == LUA_REGISTRYINDEX)
  77     return &G(L)->l_registry;
  78   else {  /* upvalues */
  79     idx = LUA_REGISTRYINDEX - idx;
  80     api_check(L, idx <= MAXUPVAL + 1, "upvalue index too large");
  81     if (ttislcf(ci->func))  /* light C function? */
  82       return NONVALIDVALUE;  /* it has no upvalues */
  83     else {
  84       CClosure *func = clCvalue(ci->func);
  85       return (idx <= func->nupvalues) ? &func->upvalue[idx-1] : NONVALIDVALUE;
  86     }
  87   }
  88 }
  89
  90
  91 /*
  92 ** to be called by 'lua_checkstack' in protected mode, to grow stack
  93 ** capturing memory errors
  94 */
  95 static void growstack (lua_State *L, void *ud) {
  96   int size = *(int *)ud;
  97   luaD_growstack(L, size);
  98 }
  99
 100
 101 LUA_API int lua_checkstack (lua_State *L, int n) {
 102   int res;
 103   CallInfo *ci = L->ci;
 104   lua_lock(L);
 105   api_check(L, n >= 0, "negative 'n'");
 106   if (L->stack_last - L->top > n)  /* stack large enough? */
 107     res = 1;  /* yes; check is OK */
 108   else {  /* no; need to grow stack */
 109     int inuse = cast_int(L->top - L->stack) + EXTRA_STACK;
 110     if (inuse > LUAI_MAXSTACK - n)  /* can grow without overflow? */
 111       res = 0;  /* no */
 112     else  /* try to grow stack */
 113       res = (luaD_rawrunprotected(L, &growstack, &n) == LUA_OK);
 114   }
 115   if (res && ci->top < L->top + n)
 116     ci->top = L->top + n;  /* adjust frame top */
 117   lua_unlock(L);
 118   return res;
 119 }
 120
 121
 122 LUA_API void lua_xmove (lua_State *from, lua_State *to, int n) {
 123   int i;
 124   if (from == to) return;
 125   lua_lock(to);
 126   api_checknelems(from, n);
 127   api_check(from, G(from) == G(to), "moving among independent states");
 128   api_check(from, to->ci->top - to->top >= n, "not enough elements to move");
 129   from->top -= n;
 130   for (i = 0; i < n; i++) {
 131     setobj2s(to, to->top, from->top + i);
 132     api_incr_top(to);
 133   }
 134   lua_unlock(to);
 135 }
 136
 137
 138 LUA_API lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf) {
 139   lua_CFunction old;
 140   lua_lock(L);
 141   old = G(L)->panic;
 142   G(L)->panic = panicf;
 143   lua_unlock(L);
 144   return old;
 145 }
 146
 147
 148 LUA_API const lua_Number *lua_version (lua_State *L) {
 149   static const lua_Number version = LUA_VERSION_NUM;
 150   if (L == NULL) return &version;
 151   else return G(L)->version;
 152 }
 153
 154
 155
 156 /*
 157 ** basic stack manipulation
 158 */
 159
 160
 161 /*
 162 ** convert an acceptable stack index into an absolute index
 163 */
 164 LUA_API int lua_absindex (lua_State *L, int idx) {
 165   return (idx > 0 || ispseudo(idx))
 166          ? idx
 167          : cast_int(L->top - L->ci->func) + idx;
 168 }
 169
 170
 171 LUA_API int lua_gettop (lua_State *L) {
 172   return cast_int(L->top - (L->ci->func + 1));
 173 }
 174
 175
 176 LUA_API void lua_settop (lua_State *L, int idx) {
 177   StkId func = L->ci->func;
 178   lua_lock(L);
 179   if (idx >= 0) {
 180     api_check(L, idx <= L->stack_last - (func + 1), "new top too large");
 181     while (L->top < (func + 1) + idx)
 182       setnilvalue(L->top++);
 183     L->top = (func + 1) + idx;
 184   }
 185   else {
 186     api_check(L, -(idx+1) <= (L->top - (func + 1)), "invalid new top");
 187     L->top += idx+1;  /* 'subtract' index (index is negative) */
 188   }
 189   lua_unlock(L);
 190 }
 191
 192
 193 /*
 194 ** Reverse the stack segment from 'from' to 'to'
 195 ** (auxiliary to 'lua_rotate')
 196 */
 197 static void reverse (lua_State *L, StkId from, StkId to) {
 198   for (; from < to; from++, to--) {
 199     TValue temp;
 200     setobj(L, &temp, from);
 201     setobjs2s(L, from, to);
 202     setobj2s(L, to, &temp);
 203   }
 204 }
 205
 206
 207 /*
 208 ** Let x = AB, where A is a prefix of length 'n'. Then,
 209 ** rotate x n == BA. But BA == (A^r . B^r)^r.
 210 */
 211 LUA_API void lua_rotate (lua_State *L, int idx, int n) {
 212   StkId p, t, m;
 213   lua_lock(L);
 214   t = L->top - 1;  /* end of stack segment being rotated */
 215   p = index2addr(L, idx);  /* start of segment */
 216   api_checkstackindex(L, idx, p);
 217   api_check(L, (n >= 0 ? n : -n) <= (t - p + 1), "invalid 'n'");
 218   m = (n >= 0 ? t - n : p - n - 1);  /* end of prefix */
 219   reverse(L, p, m);  /* reverse the prefix with length 'n' */
 220   reverse(L, m + 1, t);  /* reverse the suffix */
 221   reverse(L, p, t);  /* reverse the entire segment */
 222   lua_unlock(L);
 223 }
 224
 225
 226 LUA_API void lua_copy (lua_State *L, int fromidx, int toidx) {
 227   TValue *fr, *to;
 228   lua_lock(L);
 229   fr = index2addr(L, fromidx);
 230   to = index2addr(L, toidx);
 231   api_checkvalidindex(L, to);
 232   setobj(L, to, fr);
 233   if (isupvalue(toidx))  /* function upvalue? */
 234     luaC_barrier(L, clCvalue(L->ci->func), fr);
 235   /* LUA_REGISTRYINDEX does not need gc barrier
 236      (collector revisits it before finishing collection) */
 237   lua_unlock(L);
 238 }
 239
 240
 241 LUA_API void lua_pushvalue (lua_State *L, int idx) {
 242   lua_lock(L);
 243   setobj2s(L, L->top, index2addr(L, idx));
 244   api_incr_top(L);
 245   lua_unlock(L);
 246 }
 247
 248
 249
 250 /*
 251 ** access functions (stack -> C)
 252 */
 253
 254
 255 LUA_API int lua_type (lua_State *L, int idx) {
 256   StkId o = index2addr(L, idx);
 257   return (isvalid(o) ? ttnov(o) : LUA_TNONE);
 258 }
 259
 260
 261 LUA_API const char *lua_typename (lua_State *L, int t) {
 262   UNUSED(L);
 263   api_check(L, LUA_TNONE <= t && t < LUA_NUMTAGS, "invalid tag");
 264   return ttypename(t);
 265 }
 266
 267
 268 LUA_API int lua_iscfunction (lua_State *L, int idx) {
 269   StkId o = index2addr(L, idx);
 270   return (ttislcf(o) || (ttisCclosure(o)));
 271 }
 272
 273
 274 LUA_API int lua_isinteger (lua_State *L, int idx) {
 275   StkId o = index2addr(L, idx);
 276   return ttisinteger(o);
 277 }
 278
 279
 280 LUA_API int lua_isnumber (lua_State *L, int idx) {
 281   lua_Number n;
 282   const TValue *o = index2addr(L, idx);
 283   return tonumber(o, &n);
 284 }
 285
 286
 287 LUA_API int lua_isstring (lua_State *L, int idx) {
 288   const TValue *o = index2addr(L, idx);
 289   return (ttisstring(o) || cvt2str(o));
 290 }
 291
 292
 293 LUA_API int lua_isuserdata (lua_State *L, int idx) {
 294   const TValue *o = index2addr(L, idx);
 295   return (ttisfulluserdata(o) || ttislightuserdata(o));
 296 }
 297
 298
 299 LUA_API int lua_rawequal (lua_State *L, int index1, int index2) {
 300   StkId o1 = index2addr(L, index1);
 301   StkId o2 = index2addr(L, index2);
 302   return (isvalid(o1) && isvalid(o2)) ? luaV_rawequalobj(o1, o2) : 0;
 303 }
 304
 305
 306 LUA_API void lua_arith (lua_State *L, int op) {
 307   lua_lock(L);
 308   if (op != LUA_OPUNM && op != LUA_OPBNOT)
 309     api_checknelems(L, 2);  /* all other operations expect two operands */
 310   else {  /* for unary operations, add fake 2nd operand */
 311     api_checknelems(L, 1);
 312     setobjs2s(L, L->top, L->top - 1);
 313     api_incr_top(L);
 314   }
 315   /* first operand at top - 2, second at top - 1; result go to top - 2 */
 316   luaO_arith(L, op, L->top - 2, L->top - 1, L->top - 2);
 317   L->top--;  /* remove second operand */
 318   lua_unlock(L);
 319 }
 320
 321
 322 LUA_API int lua_compare (lua_State *L, int index1, int index2, int op) {
 323   StkId o1, o2;
 324   int i = 0;
 325   lua_lock(L);  /* may call tag method */
 326   o1 = index2addr(L, index1);
 327   o2 = index2addr(L, index2);
 328   if (isvalid(o1) && isvalid(o2)) {
 329     switch (op) {
 330       case LUA_OPEQ: i = luaV_equalobj(L, o1, o2); break;
 331       case LUA_OPLT: i = luaV_lessthan(L, o1, o2); break;
 332       case LUA_OPLE: i = luaV_lessequal(L, o1, o2); break;
 333       default: api_check(L, 0, "invalid option");
 334     }
 335   }
 336   lua_unlock(L);
 337   return i;
 338 }
 339
 340
 341 LUA_API size_t lua_stringtonumber (lua_State *L, const char *s) {
 342   size_t sz = luaO_str2num(s, L->top);
 343   if (sz != 0)
 344     api_incr_top(L);
 345   return sz;
 346 }
 347
 348
 349 #ifndef _KERNEL
 350 LUA_API lua_Number lua_tonumberx (lua_State *L, int idx, int *pisnum) {
 351   lua_Number n;
 352   const TValue *o = index2addr(L, idx);
 353   int isnum = tonumber(o, &n);
 354   if (!isnum)
 355     n = 0;  /* call to 'tonumber' may change 'n' even if it fails */
 356   if (pisnum) *pisnum = isnum;
 357   return n;
 358 }
 359 #endif
 360
 361
 362 LUA_API lua_Integer lua_tointegerx (lua_State *L, int idx, int *pisnum) {
 363   lua_Integer res;
 364   const TValue *o = index2addr(L, idx);
 365   int isnum = tointeger(o, &res);
 366   if (!isnum)
 367     res = 0;  /* call to 'tointeger' may change 'n' even if it fails */
 368   if (pisnum) *pisnum = isnum;
 369   return res;
 370 }
 371
 372
 373 LUA_API int lua_toboolean (lua_State *L, int idx) {
 374   const TValue *o = index2addr(L, idx);
 375   return !l_isfalse(o);
 376 }
 377
 378
 379 LUA_API const char *lua_tolstring (lua_State *L, int idx, size_t *len) {
 380   StkId o = index2addr(L, idx);
 381   if (!ttisstring(o)) {
 382     if (!cvt2str(o)) {  /* not convertible? */
 383       if (len != NULL) *len = 0;
 384       return NULL;
 385     }
 386     lua_lock(L);  /* 'luaO_tostring' may create a new string */
 387     luaC_checkGC(L);
 388     o = index2addr(L, idx);  /* previous call may reallocate the stack */
 389     luaO_tostring(L, o);
 390     lua_unlock(L);
 391   }
 392   if (len != NULL)
 393     *len = vslen(o);
 394   return svalue(o);
 395 }
 396
 397
 398 LUA_API size_t lua_rawlen (lua_State *L, int idx) {
 399   StkId o = index2addr(L, idx);
 400   switch (ttype(o)) {
 401     case LUA_TSHRSTR: return tsvalue(o)->shrlen;
 402     case LUA_TLNGSTR: return tsvalue(o)->u.lnglen;
 403     case LUA_TUSERDATA: return uvalue(o)->len;
 404     case LUA_TTABLE: return luaH_getn(hvalue(o));
 405     default: return 0;
 406   }
 407 }
 408
 409
 410 LUA_API lua_CFunction lua_tocfunction (lua_State *L, int idx) {
 411   StkId o = index2addr(L, idx);
 412   if (ttislcf(o)) return fvalue(o);
 413   else if (ttisCclosure(o))
 414     return clCvalue(o)->f;
 415   else return NULL;  /* not a C function */
 416 }
 417
 418
 419 LUA_API void *lua_touserdata (lua_State *L, int idx) {
 420   StkId o = index2addr(L, idx);
 421   switch (ttnov(o)) {
 422     case LUA_TUSERDATA: return getudatamem(uvalue(o));
 423     case LUA_TLIGHTUSERDATA: return pvalue(o);
 424     default: return NULL;
 425   }
 426 }
 427
 428
 429 LUA_API lua_State *lua_tothread (lua_State *L, int idx) {
 430   StkId o = index2addr(L, idx);
 431   return (!ttisthread(o)) ? NULL : thvalue(o);
 432 }
 433
 434
 435 LUA_API const void *lua_topointer (lua_State *L, int idx) {
 436   StkId o = index2addr(L, idx);
 437   switch (ttype(o)) {
 438     case LUA_TTABLE: return hvalue(o);
 439     case LUA_TLCL: return clLvalue(o);
 440     case LUA_TCCL: return clCvalue(o);
 441     case LUA_TLCF: return cast(void *, cast(size_t, fvalue(o)));
 442     case LUA_TTHREAD: return thvalue(o);
 443     case LUA_TUSERDATA: return getudatamem(uvalue(o));
 444     case LUA_TLIGHTUSERDATA: return pvalue(o);
 445     default: return NULL;
 446   }
 447 }
 448
 449
 450
 451 /*
 452 ** push functions (C -> stack)
 453 */
 454
 455
 456 LUA_API void lua_pushnil (lua_State *L) {
 457   lua_lock(L);
 458   setnilvalue(L->top);
 459   api_incr_top(L);
 460   lua_unlock(L);
 461 }
 462
 463
 464 #ifndef _KERNEL
 465 LUA_API void lua_pushnumber (lua_State *L, lua_Number n) {
 466   lua_lock(L);
 467   setfltvalue(L->top, n);
 468   api_incr_top(L);
 469   lua_unlock(L);
 470 }
 471 #endif
 472
 473
 474 LUA_API void lua_pushinteger (lua_State *L, lua_Integer n) {
 475   lua_lock(L);
 476   setivalue(L->top, n);
 477   api_incr_top(L);
 478   lua_unlock(L);
 479 }
 480
 481
 482 LUA_API const char *lua_pushlstring (lua_State *L, const char *s, size_t len) {
 483   TString *ts;
 484   lua_lock(L);
 485   luaC_checkGC(L);
 486   ts = luaS_newlstr(L, s, len);
 487   setsvalue2s(L, L->top, ts);
 488   api_incr_top(L);
 489   lua_unlock(L);
 490   return getstr(ts);
 491 }
 492
 493
 494 LUA_API const char *lua_pushstring (lua_State *L, const char *s) {
 495   lua_lock(L);
 496   if (s == NULL)
 497     setnilvalue(L->top);
 498   else {
 499     TString *ts;
 500     luaC_checkGC(L);
 501     ts = luaS_new(L, s);
 502     setsvalue2s(L, L->top, ts);
 503     s = getstr(ts);  /* internal copy's address */
 504   }
 505   api_incr_top(L);
 506   lua_unlock(L);
 507   return s;
 508 }
 509
 510
 511 LUA_API const char *lua_pushvfstring (lua_State *L, const char *fmt,
 512                                       va_list argp) {
 513   const char *ret;
 514   lua_lock(L);
 515   luaC_checkGC(L);
 516   ret = luaO_pushvfstring(L, fmt, argp);
 517   lua_unlock(L);
 518   return ret;
 519 }
 520
 521
 522 LUA_API const char *lua_pushfstring (lua_State *L, const char *fmt, ...) {
 523   const char *ret;
 524   va_list argp;
 525   lua_lock(L);
 526   luaC_checkGC(L);
 527   va_start(argp, fmt);
 528   ret = luaO_pushvfstring(L, fmt, argp);
 529   va_end(argp);
 530   lua_unlock(L);
 531   return ret;
 532 }
 533
 534
 535 LUA_API void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n) {
 536   lua_lock(L);
 537   if (n == 0) {
 538     setfvalue(L->top, fn);
 539   }
 540   else {
 541     CClosure *cl;
 542     api_checknelems(L, n);
 543     api_check(L, n <= MAXUPVAL, "upvalue index too large");
 544     luaC_checkGC(L);
 545     cl = luaF_newCclosure(L, n);
 546     cl->f = fn;
 547     L->top -= n;
 548     while (n--) {
 549       setobj2n(L, &cl->upvalue[n], L->top + n);
 550       /* does not need barrier because closure is white */
 551     }
 552     setclCvalue(L, L->top, cl);
 553   }
 554   api_incr_top(L);
 555   lua_unlock(L);
 556 }
 557
 558
 559 LUA_API void lua_pushboolean (lua_State *L, int b) {
 560   lua_lock(L);
 561   setbvalue(L->top, (b != 0));  /* ensure that true is 1 */
 562   api_incr_top(L);
 563   lua_unlock(L);
 564 }
 565
 566
 567 LUA_API void lua_pushlightuserdata (lua_State *L, void *p) {
 568   lua_lock(L);
 569   setpvalue(L->top, p);
 570   api_incr_top(L);
 571   lua_unlock(L);
 572 }
 573
 574
 575 LUA_API int lua_pushthread (lua_State *L) {
 576   lua_lock(L);
 577   setthvalue(L, L->top, L);
 578   api_incr_top(L);
 579   lua_unlock(L);
 580   return (G(L)->mainthread == L);
 581 }
 582
 583
 584
 585 /*
 586 ** get functions (Lua -> stack)
 587 */
 588
 589
 590 LUA_API int lua_getglobal (lua_State *L, const char *name) {
 591   Table *reg = hvalue(&G(L)->l_registry);
 592   const TValue *gt;  /* global table */
 593   lua_lock(L);
 594   gt = luaH_getint(reg, LUA_RIDX_GLOBALS);
 595   setsvalue2s(L, L->top, luaS_new(L, name));
 596   api_incr_top(L);
 597   luaV_gettable(L, gt, L->top - 1, L->top - 1);
 598   lua_unlock(L);
 599   return ttnov(L->top - 1);
 600 }
 601
 602
 603 LUA_API int lua_gettable (lua_State *L, int idx) {
 604   StkId t;
 605   lua_lock(L);
 606   t = index2addr(L, idx);
 607   luaV_gettable(L, t, L->top - 1, L->top - 1);
 608   lua_unlock(L);
 609   return ttnov(L->top - 1);
 610 }
 611
 612
 613 LUA_API int lua_getfield (lua_State *L, int idx, const char *k) {
 614   StkId t;
 615   lua_lock(L);
 616   t = index2addr(L, idx);
 617   setsvalue2s(L, L->top, luaS_new(L, k));
 618   api_incr_top(L);
 619   luaV_gettable(L, t, L->top - 1, L->top - 1);
 620   lua_unlock(L);
 621   return ttnov(L->top - 1);
 622 }
 623
 624
 625 LUA_API int lua_geti (lua_State *L, int idx, lua_Integer n) {
 626   StkId t;
 627   lua_lock(L);
 628   t = index2addr(L, idx);
 629   setivalue(L->top, n);
 630   api_incr_top(L);
 631   luaV_gettable(L, t, L->top - 1, L->top - 1);
 632   lua_unlock(L);
 633   return ttnov(L->top - 1);
 634 }
 635
 636
 637 LUA_API int lua_rawget (lua_State *L, int idx) {
 638   StkId t;
 639   lua_lock(L);
 640   t = index2addr(L, idx);
 641   api_check(L, ttistable(t), "table expected");
 642   setobj2s(L, L->top - 1, luaH_get(hvalue(t), L->top - 1));
 643   lua_unlock(L);
 644   return ttnov(L->top - 1);
 645 }
 646
 647
 648 LUA_API int lua_rawgeti (lua_State *L, int idx, lua_Integer n) {
 649   StkId t;
 650   lua_lock(L);
 651   t = index2addr(L, idx);
 652   api_check(L, ttistable(t), "table expected");
 653   setobj2s(L, L->top, luaH_getint(hvalue(t), n));
 654   api_incr_top(L);
 655   lua_unlock(L);
 656   return ttnov(L->top - 1);
 657 }
 658
 659
 660 LUA_API int lua_rawgetp (lua_State *L, int idx, const void *p) {
 661   StkId t;
 662   TValue k;
 663   lua_lock(L);
 664   t = index2addr(L, idx);
 665   api_check(L, ttistable(t), "table expected");
 666   setpvalue(&k, cast(void *, p));
 667   setobj2s(L, L->top, luaH_get(hvalue(t), &k));
 668   api_incr_top(L);
 669   lua_unlock(L);
 670   return ttnov(L->top - 1);
 671 }
 672
 673
 674 LUA_API void lua_createtable (lua_State *L, int narray, int nrec) {
 675   Table *t;
 676   lua_lock(L);
 677   luaC_checkGC(L);
 678   t = luaH_new(L);
 679   sethvalue(L, L->top, t);
 680   api_incr_top(L);
 681   if (narray > 0 || nrec > 0)
 682     luaH_resize(L, t, narray, nrec);
 683   lua_unlock(L);
 684 }
 685
 686
 687 LUA_API int lua_getmetatable (lua_State *L, int objindex) {
 688   const TValue *obj;
 689   Table *mt;
 690   int res = 0;
 691   lua_lock(L);
 692   obj = index2addr(L, objindex);
 693   switch (ttnov(obj)) {
 694     case LUA_TTABLE:
 695       mt = hvalue(obj)->metatable;
 696       break;
 697     case LUA_TUSERDATA:
 698       mt = uvalue(obj)->metatable;
 699       break;
 700     default:
 701       mt = G(L)->mt[ttnov(obj)];
 702       break;
 703   }
 704   if (mt != NULL) {
 705     sethvalue(L, L->top, mt);
 706     api_incr_top(L);
 707     res = 1;
 708   }
 709   lua_unlock(L);
 710   return res;
 711 }
 712
 713
 714 LUA_API int lua_getuservalue (lua_State *L, int idx) {
 715   StkId o;
 716   lua_lock(L);
 717   o = index2addr(L, idx);
 718   api_check(L, ttisfulluserdata(o), "full userdata expected");
 719   getuservalue(L, uvalue(o), L->top);
 720   api_incr_top(L);
 721   lua_unlock(L);
 722   return ttnov(L->top - 1);
 723 }
 724
 725
 726 /*
 727 ** set functions (stack -> Lua)
 728 */
 729
 730
 731 LUA_API void lua_setglobal (lua_State *L, const char *name) {
 732   Table *reg = hvalue(&G(L)->l_registry);
 733   const TValue *gt;  /* global table */
 734   lua_lock(L);
 735   api_checknelems(L, 1);
 736   gt = luaH_getint(reg, LUA_RIDX_GLOBALS);
 737   setsvalue2s(L, L->top, luaS_new(L, name));
 738   api_incr_top(L);
 739   luaV_settable(L, gt, L->top - 1, L->top - 2);
 740   L->top -= 2;  /* pop value and key */
 741   lua_unlock(L);
 742 }
 743
 744
 745 LUA_API void lua_settable (lua_State *L, int idx) {
 746   StkId t;
 747   lua_lock(L);
 748   api_checknelems(L, 2);
 749   t = index2addr(L, idx);
 750   luaV_settable(L, t, L->top - 2, L->top - 1);
 751   L->top -= 2;  /* pop index and value */
 752   lua_unlock(L);
 753 }
 754
 755
 756 LUA_API void lua_setfield (lua_State *L, int idx, const char *k) {
 757   StkId t;
 758   lua_lock(L);
 759   api_checknelems(L, 1);
 760   t = index2addr(L, idx);
 761   setsvalue2s(L, L->top, luaS_new(L, k));
 762   api_incr_top(L);
 763   luaV_settable(L, t, L->top - 1, L->top - 2);
 764   L->top -= 2;  /* pop value and key */
 765   lua_unlock(L);
 766 }
 767
 768
 769 LUA_API void lua_seti (lua_State *L, int idx, lua_Integer n) {
 770   StkId t;
 771   lua_lock(L);
 772   api_checknelems(L, 1);
 773   t = index2addr(L, idx);
 774   setivalue(L->top, n);
 775   api_incr_top(L);
 776   luaV_settable(L, t, L->top - 1, L->top - 2);
 777   L->top -= 2;  /* pop value and key */
 778   lua_unlock(L);
 779 }
 780
 781
 782 LUA_API void lua_rawset (lua_State *L, int idx) {
 783   StkId o;
 784   Table *t;
 785   lua_lock(L);
 786   api_checknelems(L, 2);
 787   o = index2addr(L, idx);
 788   api_check(L, ttistable(o), "table expected");
 789   t = hvalue(o);
 790   setobj2t(L, luaH_set(L, t, L->top-2), L->top-1);
 791   invalidateTMcache(t);
 792   luaC_barrierback(L, t, L->top-1);
 793   L->top -= 2;
 794   lua_unlock(L);
 795 }
 796
 797
 798 LUA_API void lua_rawseti (lua_State *L, int idx, lua_Integer n) {
 799   StkId o;
 800   Table *t;
 801   lua_lock(L);
 802   api_checknelems(L, 1);
 803   o = index2addr(L, idx);
 804   api_check(L, ttistable(o), "table expected");
 805   t = hvalue(o);
 806   luaH_setint(L, t, n, L->top - 1);
 807   luaC_barrierback(L, t, L->top-1);
 808   L->top--;
 809   lua_unlock(L);
 810 }
 811
 812
 813 LUA_API void lua_rawsetp (lua_State *L, int idx, const void *p) {
 814   StkId o;
 815   Table *t;
 816   TValue k;
 817   lua_lock(L);
 818   api_checknelems(L, 1);
 819   o = index2addr(L, idx);
 820   api_check(L, ttistable(o), "table expected");
 821   t = hvalue(o);
 822   setpvalue(&k, cast(void *, p));
 823   setobj2t(L, luaH_set(L, t, &k), L->top - 1);
 824   luaC_barrierback(L, t, L->top - 1);
 825   L->top--;
 826   lua_unlock(L);
 827 }
 828
 829
 830 LUA_API int lua_setmetatable (lua_State *L, int objindex) {
 831   TValue *obj;
 832   Table *mt;
 833   lua_lock(L);
 834   api_checknelems(L, 1);
 835   obj = index2addr(L, objindex);
 836   if (ttisnil(L->top - 1))
 837     mt = NULL;
 838   else {
 839     api_check(L, ttistable(L->top - 1), "table expected");
 840     mt = hvalue(L->top - 1);
 841   }
 842   switch (ttnov(obj)) {
 843     case LUA_TTABLE: {
 844       hvalue(obj)->metatable = mt;
 845       if (mt) {
 846         luaC_objbarrier(L, gcvalue(obj), mt);
 847         luaC_checkfinalizer(L, gcvalue(obj), mt);
 848       }
 849       break;
 850     }
 851     case LUA_TUSERDATA: {
 852       uvalue(obj)->metatable = mt;
 853       if (mt) {
 854         luaC_objbarrier(L, uvalue(obj), mt);
 855         luaC_checkfinalizer(L, gcvalue(obj), mt);
 856       }
 857       break;
 858     }
 859     default: {
 860       G(L)->mt[ttnov(obj)] = mt;
 861       break;
 862     }
 863   }
 864   L->top--;
 865   lua_unlock(L);
 866   return 1;
 867 }
 868
 869
 870 LUA_API void lua_setuservalue (lua_State *L, int idx) {
 871   StkId o;
 872   lua_lock(L);
 873   api_checknelems(L, 1);
 874   o = index2addr(L, idx);
 875   api_check(L, ttisfulluserdata(o), "full userdata expected");
 876   setuservalue(L, uvalue(o), L->top - 1);
 877   luaC_barrier(L, gcvalue(o), L->top - 1);
 878   L->top--;
 879   lua_unlock(L);
 880 }
 881
 882
 883 /*
 884 ** 'load' and 'call' functions (run Lua code)
 885 */
 886
 887
 888 #define checkresults(L,na,nr) \
 889      api_check(L, (nr) == LUA_MULTRET || (L->ci->top - L->top >= (nr) - (na)), \
 890         "results from function overflow current stack size")
 891
 892
 893 LUA_API void lua_callk (lua_State *L, int nargs, int nresults,
 894                         lua_KContext ctx, lua_KFunction k) {
 895   StkId func;
 896   lua_lock(L);
 897   api_check(L, k == NULL || !isLua(L->ci),
 898     "cannot use continuations inside hooks");
 899   api_checknelems(L, nargs+1);
 900   api_check(L, L->status == LUA_OK, "cannot do calls on non-normal thread");
 901   checkresults(L, nargs, nresults);
 902   func = L->top - (nargs+1);
 903   if (k != NULL && L->nny == 0) {  /* need to prepare continuation? */
 904     L->ci->u.c.k = k;  /* save continuation */
 905     L->ci->u.c.ctx = ctx;  /* save context */
 906     luaD_call(L, func, nresults, 1);  /* do the call */
 907   }
 908   else  /* no continuation or no yieldable */
 909     luaD_call(L, func, nresults, 0);  /* just do the call */
 910   adjustresults(L, nresults);
 911   lua_unlock(L);
 912 }
 913
 914
 915
 916 /*
 917 ** Execute a protected call.
 918 */
 919 struct CallS {  /* data to 'f_call' */
 920   StkId func;
 921   int nresults;
 922 };
 923
 924
 925 static void f_call (lua_State *L, void *ud) {
 926   struct CallS *c = cast(struct CallS *, ud);
 927   luaD_call(L, c->func, c->nresults, 0);
 928 }
 929
 930
 931
 932 LUA_API int lua_pcallk (lua_State *L, int nargs, int nresults, int errfunc,
 933                         lua_KContext ctx, lua_KFunction k) {
 934   struct CallS c;
 935   int status;
 936   ptrdiff_t func;
 937   lua_lock(L);
 938   api_check(L, k == NULL || !isLua(L->ci),
 939     "cannot use continuations inside hooks");
 940   api_checknelems(L, nargs+1);
 941   api_check(L, L->status == LUA_OK, "cannot do calls on non-normal thread");
 942   checkresults(L, nargs, nresults);
 943   if (errfunc == 0)
 944     func = 0;
 945   else {
 946     StkId o = index2addr(L, errfunc);
 947     api_checkstackindex(L, errfunc, o);
 948     func = savestack(L, o);
 949   }
 950   c.func = L->top - (nargs+1);  /* function to be called */
 951   if (k == NULL || L->nny > 0) {  /* no continuation or no yieldable? */
 952     c.nresults = nresults;  /* do a 'conventional' protected call */
 953     status = luaD_pcall(L, f_call, &c, savestack(L, c.func), func);
 954   }
 955   else {  /* prepare continuation (call is already protected by 'resume') */
 956     CallInfo *ci = L->ci;
 957     ci->u.c.k = k;  /* save continuation */
 958     ci->u.c.ctx = ctx;  /* save context */
 959     /* save information for error recovery */
 960     ci->extra = savestack(L, c.func);
 961     ci->u.c.old_errfunc = L->errfunc;
 962     L->errfunc = func;
 963     setoah(ci->callstatus, L->allowhook);  /* save value of 'allowhook' */
 964     ci->callstatus |= CIST_YPCALL;  /* function can do error recovery */
 965     luaD_call(L, c.func, nresults, 1);  /* do the call */
 966     ci->callstatus &= ~CIST_YPCALL;
 967     L->errfunc = ci->u.c.old_errfunc;
 968     status = LUA_OK;  /* if it is here, there were no errors */
 969   }
 970   adjustresults(L, nresults);
 971   lua_unlock(L);
 972   return status;
 973 }
 974
 975
 976 LUA_API int lua_load (lua_State *L, lua_Reader reader, void *data,
 977                       const char *chunkname, const char *mode) {
 978   ZIO z;
 979   int status;
 980   lua_lock(L);
 981   if (!chunkname) chunkname = "?";
 982   luaZ_init(L, &z, reader, data);
 983   status = luaD_protectedparser(L, &z, chunkname, mode);
 984   if (status == LUA_OK) {  /* no errors? */
 985     LClosure *f = clLvalue(L->top - 1);  /* get newly created function */
 986     if (f->nupvalues >= 1) {  /* does it have an upvalue? */
 987       /* get global table from registry */
 988       Table *reg = hvalue(&G(L)->l_registry);
 989       const TValue *gt = luaH_getint(reg, LUA_RIDX_GLOBALS);
 990       /* set global table as 1st upvalue of 'f' (may be LUA_ENV) */
 991       setobj(L, f->upvals[0]->v, gt);
 992       luaC_upvalbarrier(L, f->upvals[0]);
 993     }
 994   }
 995   lua_unlock(L);
 996   return status;
 997 }
 998
 999
1000 LUA_API int lua_dump (lua_State *L, lua_Writer writer, void *data, int strip) {
1001   int status;
1002   TValue *o;
1003   lua_lock(L);
1004   api_checknelems(L, 1);
1005   o = L->top - 1;
1006   if (isLfunction(o))
1007     status = luaU_dump(L, getproto(o), writer, data, strip);
1008   else
1009     status = 1;
1010   lua_unlock(L);
1011   return status;
1012 }
1013
1014
1015 LUA_API int lua_status (lua_State *L) {
1016   return L->status;
1017 }
1018
1019
1020 /*
1021 ** Garbage-collection function
1022 */
1023
1024 LUA_API int lua_gc (lua_State *L, int what, int data) {
1025   int res = 0;
1026   global_State *g;
1027   lua_lock(L);
1028   g = G(L);
1029   switch (what) {
1030     case LUA_GCSTOP: {
1031       g->gcrunning = 0;
1032       break;
1033     }
1034     case LUA_GCRESTART: {
1035       luaE_setdebt(g, 0);
1036       g->gcrunning = 1;
1037       break;
1038     }
1039     case LUA_GCCOLLECT: {
1040       luaC_fullgc(L, 0);
1041       break;
1042     }
1043     case LUA_GCCOUNT: {
1044       /* GC values are expressed in Kbytes: #bytes/2^10 */
1045       res = cast_int(gettotalbytes(g) >> 10);
1046       break;
1047     }
1048     case LUA_GCCOUNTB: {
1049       res = cast_int(gettotalbytes(g) & 0x3ff);
1050       break;
1051     }
1052     case LUA_GCSTEP: {
1053       l_mem debt = 1;  /* =1 to signal that it did an actual step */
1054       int oldrunning = g->gcrunning;
1055       g->gcrunning = 1;  /* allow GC to run */
1056       if (data == 0) {
1057         luaE_setdebt(g, -GCSTEPSIZE);  /* to do a "small" step */
1058         luaC_step(L);
1059       }
1060       else {  /* add 'data' to total debt */
1061         debt = cast(l_mem, data) * 1024 + g->GCdebt;
1062         luaE_setdebt(g, debt);
1063         luaC_checkGC(L);
1064       }
1065       g->gcrunning = oldrunning;  /* restore previous state */
1066       if (debt > 0 && g->gcstate == GCSpause)  /* end of cycle? */
1067         res = 1;  /* signal it */
1068       break;
1069     }
1070     case LUA_GCSETPAUSE: {
1071       res = g->gcpause;
1072       g->gcpause = data;
1073       break;
1074     }
1075     case LUA_GCSETSTEPMUL: {
1076       res = g->gcstepmul;
1077       if (data < 40) data = 40;  /* avoid ridiculous low values (and 0) */
1078       g->gcstepmul = data;
1079       break;
1080     }
1081     case LUA_GCISRUNNING: {
1082       res = g->gcrunning;
1083       break;
1084     }
1085     default: res = -1;  /* invalid option */
1086   }
1087   lua_unlock(L);
1088   return res;
1089 }
1090
1091
1092
1093 /*
1094 ** miscellaneous functions
1095 */
1096
1097
1098 LUA_API int lua_error (lua_State *L) {
1099   lua_lock(L);
1100   api_checknelems(L, 1);
1101   luaG_errormsg(L);
1102   /* code unreachable; will unlock when control actually leaves the kernel */
1103   return 0;  /* to avoid warnings */
1104 }
1105
1106
1107 LUA_API int lua_next (lua_State *L, int idx) {
1108   StkId t;
1109   int more;
1110   lua_lock(L);
1111   t = index2addr(L, idx);
1112   api_check(L, ttistable(t), "table expected");
1113   more = luaH_next(L, hvalue(t), L->top - 1);
1114   if (more) {
1115     api_incr_top(L);
1116   }
1117   else  /* no more elements */
1118     L->top -= 1;  /* remove key */
1119   lua_unlock(L);
1120   return more;
1121 }
1122
1123
1124 LUA_API void lua_concat (lua_State *L, int n) {
1125   lua_lock(L);
1126   api_checknelems(L, n);
1127   if (n >= 2) {
1128     luaC_checkGC(L);
1129     luaV_concat(L, n);
1130   }
1131   else if (n == 0) {  /* push empty string */
1132     setsvalue2s(L, L->top, luaS_newlstr(L, "", 0));
1133     api_incr_top(L);
1134   }
1135   /* else n == 1; nothing to do */
1136   lua_unlock(L);
1137 }
1138
1139
1140 LUA_API void lua_len (lua_State *L, int idx) {
1141   StkId t;
1142   lua_lock(L);
1143   t = index2addr(L, idx);
1144   luaV_objlen(L, L->top, t);
1145   api_incr_top(L);
1146   lua_unlock(L);
1147 }
1148
1149
1150 LUA_API lua_Alloc lua_getallocf (lua_State *L, void **ud) {
1151   lua_Alloc f;
1152   lua_lock(L);
1153   if (ud) *ud = G(L)->ud;
1154   f = G(L)->frealloc;
1155   lua_unlock(L);
1156   return f;
1157 }
1158
1159
1160 LUA_API void lua_setallocf (lua_State *L, lua_Alloc f, void *ud) {
1161   lua_lock(L);
1162   G(L)->ud = ud;
1163   G(L)->frealloc = f;
1164   lua_unlock(L);
1165 }
1166
1167
1168 LUA_API void *lua_newuserdata (lua_State *L, size_t size) {
1169   Udata *u;
1170   lua_lock(L);
1171   luaC_checkGC(L);
1172   u = luaS_newudata(L, size);
1173   setuvalue(L, L->top, u);
1174   api_incr_top(L);
1175   lua_unlock(L);
1176   return getudatamem(u);
1177 }
1178
1179
1180
1181 static const char *aux_upvalue (StkId fi, int n, TValue **val,
1182                                 CClosure **owner, UpVal **uv) {
1183   switch (ttype(fi)) {
1184     case LUA_TCCL: {  /* C closure */
1185       CClosure *f = clCvalue(fi);
1186       if (!(1 <= n && n <= f->nupvalues)) return NULL;
1187       *val = &f->upvalue[n-1];
1188       if (owner) *owner = f;
1189       return "";
1190     }
1191     case LUA_TLCL: {  /* Lua closure */
1192       LClosure *f = clLvalue(fi);
1193       TString *name;
1194       Proto *p = f->p;
1195       if (!(1 <= n && n <= p->sizeupvalues)) return NULL;
1196       *val = f->upvals[n-1]->v;
1197       if (uv) *uv = f->upvals[n - 1];
1198       name = p->upvalues[n-1].name;
1199       return (name == NULL) ? "(*no name)" : getstr(name);
1200     }
1201     default: return NULL;  /* not a closure */
1202   }
1203 }
1204
1205
1206 LUA_API const char *lua_getupvalue (lua_State *L, int funcindex, int n) {
1207   const char *name;
1208   TValue *val = NULL;  /* to avoid warnings */
1209   lua_lock(L);
1210   name = aux_upvalue(index2addr(L, funcindex), n, &val, NULL, NULL);
1211   if (name) {
1212     setobj2s(L, L->top, val);
1213     api_incr_top(L);
1214   }
1215   lua_unlock(L);
1216   return name;
1217 }
1218
1219
1220 LUA_API const char *lua_setupvalue (lua_State *L, int funcindex, int n) {
1221   const char *name;
1222   TValue *val = NULL;  /* to avoid warnings */
1223   CClosure *owner = NULL;
1224   UpVal *uv = NULL;
1225   StkId fi;
1226   lua_lock(L);
1227   fi = index2addr(L, funcindex);
1228   api_checknelems(L, 1);
1229   name = aux_upvalue(fi, n, &val, &owner, &uv);
1230   if (name) {
1231     L->top--;
1232     setobj(L, val, L->top);
1233     if (owner) { luaC_barrier(L, owner, L->top); }
1234     else if (uv) { luaC_upvalbarrier(L, uv); }
1235   }
1236   lua_unlock(L);
1237   return name;
1238 }
1239
1240
1241 static UpVal **getupvalref (lua_State *L, int fidx, int n, LClosure **pf) {
1242   LClosure *f;
1243   StkId fi = index2addr(L, fidx);
1244   api_check(L, ttisLclosure(fi), "Lua function expected");
1245   f = clLvalue(fi);
1246   api_check(L, (1 <= n && n <= f->p->sizeupvalues), "invalid upvalue index");
1247   if (pf) *pf = f;
1248   return &f->upvals[n - 1];  /* get its upvalue pointer */
1249 }
1250
1251
1252 LUA_API void *lua_upvalueid (lua_State *L, int fidx, int n) {
1253   StkId fi = index2addr(L, fidx);
1254   switch (ttype(fi)) {
1255     case LUA_TLCL: {  /* lua closure */
1256       return *getupvalref(L, fidx, n, NULL);
1257     }
1258     case LUA_TCCL: {  /* C closure */
1259       CClosure *f = clCvalue(fi);
1260       api_check(L, 1 <= n && n <= f->nupvalues, "invalid upvalue index");
1261       return &f->upvalue[n - 1];
1262     }
1263     default: {
1264       api_check(L, 0, "closure expected");
1265       return NULL;
1266     }
1267   }
1268 }
1269
1270
1271 LUA_API void lua_upvaluejoin (lua_State *L, int fidx1, int n1,
1272                                             int fidx2, int n2) {
1273   LClosure *f1;
1274   UpVal **up1 = getupvalref(L, fidx1, n1, &f1);
1275   UpVal **up2 = getupvalref(L, fidx2, n2, NULL);
1276   luaC_upvdeccount(L, *up1);
1277   *up1 = *up2;
1278   (*up1)->refcount++;
1279   if (upisopen(*up1)) (*up1)->u.open.touched = 1;
1280   luaC_upvalbarrier(L, *up1);
1281 }
1282
1283